Fixed dangling snackbar in NearbyFragment

[zhao-gang]

Summary:

'Internet unavailable' snackbar doesn't disappear after network becomes available in NearbyFragment

Steps to reproduce:

Make network unavailable in Nearby fragment, the 'Internet unavailable' snackbar shows, then make network available, the snackbar doesn't disappear.

Device and Android version:

Unrelated

Commons app version:

master betaDebug

Would you like to work on the issue?

Yes

[deniger]

Hello,

I take a look to the fragment NearbyFragment and I notice that the method addNetworkBroadcastReceiver is called each time the tab is selected. This method creates a new Snackbar and register a BroadcastReceiver to the activity. So these 2 actions are done each time the tab is selected. I could explain this bug even if I didn't managed to reproduce it ( enabling/disabling airplane mode).

I suppose that registering the broadcaster receiver should be done in the method onCreate and the snackbar should be created only if internet is unavailable.

Am I correct ?

[zhao-gang]

@deniger Yes, currently the broadcast receiver is registered every time the tab is selected. My PR added a test in method addNetworkBroadcastReceiver. It first checks whether broadcastReceiver is null, if it's null we create the broadcastReceiver and register it, if it's not null(meaning a broadcastReceiver has already been created and registered), just skip the creation and registration of broadcastReceiver. I think that's enough to prevent registering multiple broadcastReceivers. Please correct me if I'm wrong :-)

[deniger]

@zhao-gang my mistake: I didn't see your PR. I need 👓 ...